Apparatus for controlling the unwinding of web



ETA. 3,414,208

APPARATUS FOR CONTROLLING THE UNWNDING OF' WEB Dec. 3, 1968 R. A. BUTLER, JR.,

8 Sheets-Sheet l Filed Sept. 2, 1966 2:1 Inl/enfans /Pz'cizaro A. But/er, Jh

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Dec. 3, 1968 R. A. BUTLER, JR ET AL 3,414,208

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APPARATUS FOR CONTROLLING THE UNWINDING OF WEB Filed Sept, 2, 1966 4 8 Sheets-Sheet 7 Eig. Il my 154 a 12%/ L'I f L mi YM (/f United States Patent O 3,414,208 APPARATUS FOR CONTROLLING r[HE UNWINDING F WEB Richard A. Butler, Jr., Brookline, and Edward P. Ziedelis,

Canton, Mass., and Richard T. Martin, Chicago, Ill., assignors, by mesne assignments, to Richard A. Butler, Jr., Brookline, Mass.

Filed Sept. 2, 1966, Ser. No. 577,024 15 Claims. (Cl. 242-58.1)

The present invention relates generally to improvements in apparatus for controlling the unwinding of web. More particularly, in at least one of its aspects the invention relates to apparatus adapted to being interposed between a web supply roll and a web consuming machine requiring web either continuously or intermittently at a high average speed. The apparatus is of the type which stores a quantity of web in motion and controls the stored web either increasing or decreasing the stored quantity to compensate for variations in demand speed and also to permit a reduction in web speed or stopping of the web at a splicing position without reducing web speed to the web consuming machine.

A broad object of the invention is to provide a large quantity of web storage in a minimum amount of floor area which is usually at a premium around web consuming machines such as high speed presses, for example.

Another object of the invention is to permit variations in the quantity of stored web without requiring members to which a high degree of momentum is imparted.

Yet another object is to provide for greater and longer web conditioning than has heretofore been possible with conventional apparatus. The conditioning of web before it reaches a web consuming machine such as a printing press is important for providing optimum conditions of moisture content, tension, curl elimination and surface for superior printing.

Still another object is to permit the formation of a splice between a new 'web supply roll and a running web at a point on the web which is either moving at a very low speed or has been completely stopped while the web consuming machine continues being fed at its normal speed.

Still another object is to maintain effective control of differences in input and output rates to web storage apparatus.

In the achievement of the foregoing objects, a feature of the invention relates to a festoon comprising at least one set, usually more, of rolls rotatable about stationary axes, hereinafter referred to as the idler rolls, and another set of rolls, called the dancer rolls, mounted upon a yoke for movement toward and away from the idler rolls. Each set of idler and dancer rolls comprises at least two rolls of different diameters with the smaller roll in each case being positioned nearer the other set, that is the smaller idler roll is located nearer the set of dancer rolls and vice versa. The two sets of rolls define between them a path for two bights of Iweb or a storage capacity of web approximately equal in length to four times the mean distance between the two sets of rolls at any given time. It will be seen that this feature contributes not only to the storage of a maximum quantity of web in a given amount of floor space but also and perhaps more importantly by reducing the speed at which the dancer rolls and yoke move toward and away from the idler rolls momentum of the web controlling parts.

According to another feature of the invention, accurate control is maintained over the excess of input to the festoon over the output from the festoon to the web consuming machine. As a new web supply roll is started in operation, for example, the new roll must be accelerated to the average demand speed of the web consuming limits the Patented Dec. 3, 1968 lCC machine. During this time the output rate from the festoon is considerably greater than the input rate and the difference in rates is mad-e up by movement of the dancer rolls toward the idler rolls. In the acceleration of the new roll, however, a point is reached when the input to the festoon equals and then exceeds the output to the web consuming machine. This excess of web is absorbed by movement of the dancer rolls away from the idler rolls. According to the control feature of the invention, this excess of input over output of the festoon is sensed and a variable braking force is applied to the web supply roll at a rate proportional to the rate of movement of the dancer rolls away from the idler rolls. According to a related feature of the invention the braking force applied to the web supply roll is also varied as the festoon approaches a filled condition. Thus, as the filling is becoming completed, the braking force to the web supply roll is inversely proportional to the amount of web storage space remaining in the dancer assembly.

The objects and features of the present invention and many advantages accruing from its use will be clarified from a detailed description of an illustrative embodiment taken in connection with the accompanying drawings, in which:

FIG. 1 is a view in left side elevation of web supply apparatus according to the present invention;

FIG. 2 is a view in front elevation of the apparat-us depicted in FIG. 1;

FIG. 3 is a view in perspective and with some of the parts shown in exploded relationship and with others omitted for clarity, illustrating operating and control connections to a dancer assembly forming a part of a festoon or storage device in the present apparatus;

FIG. 4 is a detail plan view illustrating a brake assembly associated with each web supply roll position in the present apparatus;

FIGS. 5 and 6 are fragmentary detail views in left side elevation and plan respectively of parts of the dancer assembly;

FIGS. 7 and 8 are largely schematic views in left side elevation of a double dancer roll configuration respectively illustrating operating and start-up conditions;

FIGS. 9 and 10 are views similar to FIGS. 7 and 8 but illustrating a triple dancer roll configuration respectively under operating and start-up conditions;

FIG. 11 is a schematic diagram of pneumatic connections of the present apparatus; and

FIG. 12 is a schematic diagram illustrating electrical connections of the present apparatus.

Turning now to the drawings, apparatus according to the present invention is illustrated as comprising a frame including upright parallel side plates 20 and 22 maintained in spaced relationship by horizontal frame members typically illustrated at 24, 26 and 28 in FIGS. 1 and 2. Supported at the front of the frame is a web storage festoon indicated generally at 30, upper and lower web unwind stations at which web supply rolls 32 and 34 are respectively supported, and a web splicing device indicated generally at 36. In this application the web splicing device 36 is not described in detail. For purposes of a better understanding of the present apparatus, the splicing device 36 may be considered as similar except as otherwise indicated to that disclosed in application for Letters Patent of the United States Serial No. 419,969, filed December 21, 1964 in the names of Richard A. Butler, Ir. and Norton T. Pierce and now Patent No. 3,305,189 issued February 21, 1967.

The web storage festoon 30 in the present apparatus is best seen in FIGS. 1, 7 and 8 in a double roll conguration which approximately doubles the storage capacity obtainable with the design of the above identified application, within the same parameters of floor area and height. The number of rolls in each set may be increased to a triple roll configuration, as depicted in FIGS. 9 and l0. For purposes of clarity however the double roll configuration will first Ibe described in detail and thereafter the manner in which more rolls may be employed to increase still further the storage capacity will be clarified. In the double roll configuration a plurality of pairs of rolls each rotatable about a stationary axis and generally referred to as idler rolls cooperate with pairs of dancer rolls mounted on a yoke movable toward and away from the idler rolls and hence each dancer roll rotates about a movable axis. Each pair of rolls whether idler rolls or dancer rolls consists of different diameters, the larger roll being mounted outboard and the smaller roll being mounted inboard.

Although the double roll configuration may be ernployed with as few as one pair of idler rolls and one pair of dancer rolls, there is shown in the drawings a typical installation comprising four pairs of idler rolls and four pairs of dancer rolls. The outboard idler rolls, that is those most remote from the dancer rolls are designated by reference numerals 38, 40, 42 and 44 and these outboard idler rolls are paired respectively with inboard idler rolls 46, 48, 50 and 52. It will later be seen that a substantial advantage is obtained from mounting the dancer rolls so that their path of travel is offset from the axial planes of the nearest pairs of idler rolls to permit lowering the dancer rolls between the idler rolls. The outboard dancer rolls, those most remote from the idler rolls, are designated by the reference numerals 54, 56, 58 and 60 paired respectively with inboard dancer rolls 62, 64, 66 and 68. The construction and mounting of the rolls whether idler or dancer is essentially the same and is illustrated in FIG. 6 in which the dancer roll 56 is partially sectioned and shown to be of relatively thin-walled tubular construction and supported on a shaft 70 one end of which is fixed to a yoke plate 72. The other end of the shaft as shown in FIG. 2 is xedly supported in a yoke plate 74 at the right side of the apparatus. Interposed between each end of the roll 56 and the shaft 70 is a ball bearing assembly 76 retained on the shaft 70 by a collar 78. Each of the idler rolls is similarly mounted on a shaft fixedly supported between brackets 79 seen in FIG. 2 and forming a part of the frame.

The plates 72 and 74, the shafts 70 and the dancer rolls, together comprising the dancer assembly collectively identified by the reference numeral 80, move together away from the idler rolls whenever the input rate to the storage festoon exceeds the output rate to the web consuming machine. Conversely, when the output rate from the storage festoon exceeds the input rate, the dancer assembly 80 moves toward the idler rolls. For guiding the movement of the dancer assembly 80 toward and away from the idler rolls, there is provided at the sides of the machine as seen in FIGS. l, 2, and 6 a pair of guide rails 86 and 88 supported in parallel relationship, on the plates and 22 respectively. As seen in FIG. 6, the guide rail 86 is in the form of a shallow channel including a pair of spaced apart, nturned legs 90 and a laterally disposed tenon 92. The guide rail 88 is essentially the mirror image of the guide rail 86 except that the rail 88 is not provided with the equivalent of the tenon 92 and the couplings of the plate 74 to the rail 88 is otherwise exactly the same as the coupling of the plate 72 to the rail 86. In the interest of brevity therefore only the coupling of the plate 72 to the rail 86 will be described with reference to FIGS. 5 and 6. The legs of the rail 86 are closely embraced by ball bearing rolls 94 each mounted on a threaded stud 96 to prevent displacement of the plate 72 in a plane normal to the axes of the shafts 70. In order to prevent displacement of the plate 72 in a direction parallel to the axes of the shafts 70, the tenon 92 is embraced by a pair of ball bearing mounted rolls 98 each Supported 911 .21 stud .100

iixedly mounted on a bracket 102 which is in turn aixed to the plate 72. The engagement of the rolls 94 and 98 with the legs and the tenon 92 together with a similar coupling between the plate 74 and the rail 88 provides a low friction but accurate guidance for the motion of the dancer assembly 80.

Mechanism for urging the dancer assembly 80 upwardly to store web will be described with reference to FIGS. l, 2, and 3. The mechanism includes a pair of endless roller chains 104 and 106 each arranged to form a closed loop and coupled respectively to the plates 72 and 74. Both the chains 104 and 106 are similarly arranged and so only the disposition of the chain 104 will be described in detail. The chain 104 is connected at its ends to an anchor block 108 secured to the inside of the plate 72 to form a closed loop guided by lower idler sprockets 110 and 112, upper idler sprocket 114 and trained over a large drive sprocket 116. The chain 104 also meshes with a switch control sprocket 118 keyed to a short shaft 120 which is journalled in the side plate 20. The sprocket 116 is keyed to a transverse shaft 122 which is journalled near its ends in the plates 20 and 22.

The necessary force -for urging the dancer assembly upward to store web is provided by a pair of pistons 124 and 126, shown only schematically in FIG. 1l, slidable in cylinders 128 and 130. The pistons 124 and 126 are respectively mounted on rods 132 and 134. In the drawings, particularly FIGS. 1 and 3, only the cylinder -128 and the piston rod 132 are shown but the same connections are duplicated for the rod 134. There is connected to the rod 132 a roller chain 136 which is wrapped about a sprocket 138 keyed to the shaft 122. As a result, when the piston 124 is pressed downwardly under air pressure the shaft 122 and the sprocket 116 are caused to rotate in a counterclockwise direction as seen in FIGS. 1 and 3 and, through the coupling provided by the chain 104 to the plate 72, urge the dancer assembly to store a greater `quantity of web as the dancer rolls move upwardly. The length of travel or stroke of the piston `124 is translated through the relative pitch diameters of the sprockets 138 and y116 to provide a travel for the dancer assembly yfrom the lowermost position seen in FIG. 8 to a fully loaded position somewhat higher than that shown in FIGS. l and 7. The ratio of the pitch circumference of the sprocket 116 to the total travel of the dancer assembly is such that as the dancer .assembly travels from its empty to its full position, the sprocket 1116 and the shaft 122 turn somewhat less than a complete revolution.

In order to control the braking `force applic-d to the roll of running web there is mounted on the shaft 122 at a point outside the plate 20 a cam 140 the periphery of which is engaged by a follower roll 142 which is a part olf a commercially available pressure regulating valve 144. There is also mounted on the shaft 122, a second cam 146 which engages a roller 148 for actuating a normally closed damper cut-off switch 150. The valve 144 and the switch 150 are mounted respectively on brackets 152 and 154 both secured to the outside of the plate 20.

There is provided in the present apparatus a device for sensing the condition under which weib input to the festoon 30 exceeds web output to the web consuming machine. Under these conditions the dancer assembly 80 rises at a speed which is proportional to the distance between the input and the output speeds. The sensing device includes a normally open damper switch .160 provided with an actuating arm 162 which causes the switch to close only when the distal end of the arm is deected downwardly. For actuating the switch there 1s provided a pinion 164 in mesh with a gear 166 fixedly mounted on the shaft 120. The pinion 164 is rotatable about a stu-d 168 and has projecting into the path 0f 1t s teeth the `distal end of the arm `162 so that as the pinion 164 rotates each tooth deflects the switch operating arm. However, only rotation of the pinion in the counterclockwise direction as seen in FIG. 3 causes closing of the switch l160` by depressing the arm 162. Rotation of the pinion 160 in the opposite direction although raising the arm 1-62 has no effect in closing the switch. It is thus seen that as the dancer assembly 80 rises, the switch 160 is closed once for each tooth of the pinion 164 engaging the ,arm 162. The Igear 166 and the pinion `164 may be varied in their ratio and thus change the number of times the switch 160 is closed to correspond to a predetermined rise o-f the dancer assembly 80. It will be seen below that the number of closing pulses of the switch 160` during a given time interval is translated into an effective braking force proportional to the speed at which the dancer assembly 80 is rising. The damper switch as will also be seen below is effective during the lower two-thirds off the travel of the dancer assembly 80 and contributes to greater overall control of the unwinding of the web.

In the present apparatus, web supply rolls are mounted on expanding arbors generally of the type disclosed in the .above identified application. The arbor is similarly supported for rotation on sets of rollers, omitted from the present drawings, mounted on pairs of upper and lower loading brackets `172 and V174 fixedly secured in spaced relationship inside the plates and 22. At each unwind station, devices are provi-ded for coupling the web supply roll to a brake and for assisting in movin-g the roll axially to bring its edges into vertical register with those of the roll at the other unwind station. These devices shown in FIG. 1 and more particularly in FIG. 4 include a chuck 176 formed at its inboard end with an appropriate socket 178 to receive a complementary end formed on a roll supporting anbor shown fragmentarily at 179. The chuck 176 is tubular and affixed by a pin -180 to a head 182 formed integral at the inboard end of a horizontal shaft 184. The interior of the chuck y176 is formed with a key-way 186 to slide over .a key 188 fixed in a sleeve 190 which is machined to a sliding tit inside the chuck 176. The sleeve 190 is rotatable in bearings 192 mounted in a barrel I194 fixed to a plate 195 fxedly supported outside the side plate 20 to permit the chuck 176 to engage. the arbor 179. Outboard from the bearings 192 there is keyed to the sleeve 190 a hub 196 to which a brake disc 198 is affixed. The hub 196 is retained on the sleeve 190 by a nut 200 threaded on the outboard portion of the sleeve. Thus, the assembly comprising the chuck 176, the shaft y184, the sleeve 190 and the brake disc 198 rotates as a unit in the bearings `192. The shaft 184 and the chuck 176 however are free to slide axially with respect to the sleeve 190 in order to align each new web supply roll with the roll at the other web unwind station. For this purpose the outboard end of the shaft 184 is fitted in a ball bearing 206 retained in an adapter socket -208 formed integral with the inboard end of a screw 210. In order to maintain the socket 208 and the screw 210 against rotation, the socket is iixedly retained within :a slotted ring 212 in the slot of which a guide finger 214 is slidable. The 'guide finger 214 is fixed to a plate 216 in turn fixedly supporte-d in spaced relationship on the plate 195. A nut -218 in threaded engagement with the screw 210 is rotatable in a ball bearing 220 by means of a hand wheel 222 to cause motion to the chuck 176 in Vand out, away from and toward the plate 20 to yalign the web roll. The bearing 220 is retained on the nut 218 by a snap rin-g 224 and on the 'plate 216 by a cap 226 having an internal snap ring 228. In order to apply a braking force to the roll associated with the chuck 176 there are bearing on the brake disc 198 pairs of opposed brake pads 230, part of a commercially available brake assembly 232 which is xedly supported upon the plate 195. The apparatus illustrated in FIG. 4 is duplicated at the lower web unwind station, that occupied by the web roll 34. At the lower web station, the brake assembly is designated by the reference numeral 234` and includes brake pads 236 engaging a brake disc 238 as shown schematically in FIG. 11.

In the present apparatus air under pressure is supplied to the brake pads 230, 236, the dancer cylinders 128 and 130 and to air cylinders for performing splicing and web severing functions through a compressed air line 248 yshown schematically in FIG. 11. The line 248 is preferably maintained at a regulated pressure of between l0() and 150 p.s.i., under average conditions of web width, tensile strength, and demand speed. When very wide webs a-re to be controlled or the consuming speeds are elevated, it may be necessary to increase the pressure available at the line 248. From the main line 248 the air passes through a filter 250, a manually adjustable main pressure regulator 252 provided with a. pressure gauge 253 and through a lubricator 254 to a machine -distribution line 256. There is interposed between the junction of the line 256 with the lubricator 254 and the cylinders 128 and 130, a manually operated dancer shut-off valve 258 so that air to the cylinders may be cut off in placing the apparatus in service or at any other time when a new web is to be threaded through the dancer assembly as will be more fully understood below. From the valve 258 compressed air passes through a manually adjustable pressure regulating valve 260 provided with a pressure gauge 262 used to regulate the amount of force acting to store web in the storage festoon and through flow control devices including a check valve 264 in parallel with a manually adjustable restriction 266 to the cylinders 128 and 130. The .restriction 266 limits the flow of air from above the pistons 124 and 126 as the web output speed exceeds the input speed to the festoon 38, thereby increasing web tension and accelerating the running web roll. In a conduit 268 interconnecting thevalves 264 and 266 with the cylinders 128 and 130, there is also a manually adjustable pressure relief valve 270 and a manually operable bleeder valve 272.

A second branch of the pneumatic circuit is connected to the distribution line 256` through a pressure regulating valve 278 which is provided with a pressure gauge 280. From the output side of the pressure regulating valve 278 there are connections to two cylinders 282 and 284 in which are respectively mounted pistons 286 and 288 for performing splicing and web severing functions. In the present apparatus the linear motion of the pistons 286 and 288 is substituted for the rotary motion of solen-oids described for the splicing and web cutting functions in the above identified application. Both the pistons 286 and 288 are shown in their inactive positions, that which they occupy between web splicing operations. In order to splice the leading end of a roll from the upper unwind station, that occupied by the roll 32 in FIG. l, the piston 286 is urged upwardly by compressed air in the cylinder 282 and this rise of the p-iston 286 also accomplishes the cutting off of the running web coming from the lower unwind station, that occupied by the roll 34 in FIG. l. For splicing the leading end of a roll of web at the lower unwind station, the piston 288 is urged upwardly by compressed air in the cylinder 284 and this rise of the piston 288 also accomplishes the cutting off of web from the upper unwind station. Compressed air is supplied to the cylinder 282 through a solenoid operated valve including a spool 290 actuated by a solenoid 292. Similarly, air is supplied to the cylinder 284 through an identical valve including a spool 294 actuated by a solen-oid 296.

The connections -bringing a supply of compressed air to the brake pads 230 and 236 comprise the pressure regulating valve 144 whose output pressure is controlled by the cam The shape of the cam 140 is such that it depresses a plunger 298 of the valve 144 only while the dancer rolls are in the upper third of their travel. The effect of depressing the plunger 298 is to increase the output pressure of the valve 144. At times when the plunger 298 is not depressed the output pressure of the valve 144 is at a preset minimum. The output of the regulator valve 144 is in communication with the brake shoes 230 and 236 through connections which include a solenoid operated valve comprising a spool 300 actuated by a solenoid 302. While the solenoid 302 is de-energized and the spool is in the position depicted in FIG. 11, the output of the valve 144 is in communication through the upper half of the spool 300 with a shuttle valve 304 the function of which will be explained below. The solenoid 302 is energized to shift the spool 300 upwardly and thereby place in communication with the shuttle valve 304, a decelerating air circuit comprising a pressure regulator 306 which is manually adjustable and provided with a pressure gauge 308. Interposed between the pressure regulator valve 306 and the shuttle valve 304 is a manually adjustable restriction 310y in the form of a needle valve. The pressure regulator 306 is normally adjusted to a higher pressure than the maximum tension control pressure obtainable from the valve 144 but the presence of the valve 310 in the circuit allows a gradual build-up in air pressure at the brakes during the decelerating cycle. This gradual build-up of air pressure is important to avoid rupture of the web either when the web vbeing operated upon is somewhat fragile in character or the web supply roll at the start of the deceleration cycle is still of considerable size and accordingly subject to substantial momentum.

Connected to an end of the valve 304 opposite that to which the output of the spool 300 is connected is a damping circuit including a pressure regulator 312 which is manually adjustable and provided with a pressure gauge 314. The output of the valve 312 is connected to the shuttle valve 304 through a solenoid operated valve including a spool 316 actuated by a solenoid 318. When the solenoid 318 is energized and the spool 316 is lowered as seen in FIG. l1, the output of the pressure regulating valve 312 is placed in communication with the shuttle valve 304. It is thus seen that the output to the valve 304 consists either o-f a steady pressure supplied from the pressure regulator 144 through the spool 300 or pulses of a greater pressure from the regulator 3l2 supplied to the valve 304 through the upper portion of the spool 316. In any event the output lof the valve 304 is communicated either to both sets of brake pads 230 and 236 or to the appropriate set of brake pads through a manually adjustable three-way valve including a spool 320. While the spool 320 is in its central position as shown in FIG. l1 the output of the valve 304 is applied to both sets of brake pads 230 and 236. When the spool 320 is raised so that its lower third becomes operative, the output of the valve 304 is placed in communication with the pads 230, while the pads 236 are maintained at atmospheric pressure also through the same lower third of the spool 320. When the spool 320 is shifted downwardly so that its upper third is placed vin operative position, the output of the shuttle valve 304 is communicated through this upper third to the brake pads 236 while the pads 230 are returned to atmosphere through the same third of the spool 320. The operator of the apparatus therefore maintains the spool 320 in its central position whenever conditions arise which make desirable that braking force be appliedgat both the upper and lower unwind stations; the spool 320 is raised to control the unwinding at the upper station and lowered to control the unwinding at the lower station.

Electrical connections of the apparatus derive their power from the secondary winding of a transformer 330, one side of which is connected to a main machine line 332 through a fuse 334 and the other side of which is connected to a line 336. Connected between the lines 332 and 336 is a Vsplice cycle initiating circuit including a normally closed pushbutton stop switch 338 and a normally open pushbutton switch 340which when it is temporarily closed causes a secondary line 342 to be energized. Circuits for controlling deceleration of the running web preparatory to formation of a splice and to control the formation of the splice are interposed between the secondary line 342 and the line 336. A primary control circuit includes a pair of normally closed contacts TD24A in series with a relay coil 1CR which is equipped with two sets of contacts. The first set of contacts ICR-A is normally open but when the relay coil ICR is energized the contacts close to start a motor 344 for driving a vacuum pump. The pump performs essentially the same function of holding the leading end of the ready web in position for the formation of a splice as in the apparatus of the above-identified application. The circuit for the motor 344 also includes a pair of normally closed overload protection contacts 346 in series with the motor. The second pair of contacts actuated by the relay coil lCR is normally open contacts lCR-B in parallel with the switch 340. Thus, when the switch 340 is closed temporarily and the relay coil ICR is energized, the contacts ICR-B close to keep the secondary line 342 energized after the switch 340 is allowed to open. A pilot light 348 is provided to signal that the apparatus is ready for the performance of a splicing operation when the line 342 is energized.

The splicing cycle may be initiated either upon command or automatically by the use of the present apparatus, as is also the case with the apparatus of the above identified application. In order to initiate a splicing cycle upon command a normally open push button switch 350 is closed temporarily. The splicing cycle is initiated automatically by the closure of either of switches 352 and 354 which continually sense the size of the roll of unwinding web. The switches 352 and 354 are in parallel with the switch 350 and the momentary closure of any one of them causes a relay coil 2CR to become energized thereby closing a single pair of normally open contacts ZCR-A to latch in the relay coil 2CR after the switch which has closed only momentarily is allowed to open. There is also energized from the secondary line 342 through the closed contacts ZCR-A, a time delay relay coil TD1 having two sets of contacts. The relay operated by the coil TD1 is adjustable to change the normal position of its conta-cts at the end of a brief interval of time typically approximately one second after the relay coil TD1 is energized allowing normally closed contacts TD1-A to open and normally open contacts TD1-B to close. Thus the solenoid 302 is energized for a period of approximately one second after the relay coil TD1 is energized. Energization of the solenoid 302 occurs through the normally closed contacts TD1-A and the relay contacts ZCR-A. The elfect of energizing the solenoid 302 is to shift the spool 300 as seen in FIG. 11 from its lower to its upper position thereby disconnecting the shuttle valve 304 from the pressure regulator 144 and connecting the shuttle valve to the pressure regulator 306. The pressure supplied by the regulator 306 is such that even a full web roll is brought to a complete stop during the interval of one second for which the relay operated by the coil TD1 is set.

At the end of the one second interval the web at the web splicing device 36 is stationary and the splice is formed automatically. The formation of the splice occurs when the contacts TD1-B close and thereby energize either the solenoid 292 or the solenoid 296 depending upon the position of a selector switch 356 which may advantageously be coupled to devices for supporting the leading end of the ready web or to devices for severing the running web or may alternatively be manually operated. In the position in which the switch 356 is depicted in FIG. 12, the solenoid 296 is energized causing the spool 294 to rise as seen in FIG. l1 thereby connecting the lower chamber in the cylinder 284, that below the piston 288, to the output of the pres/sure regulator 278 and the upper chamber to atmosphere. As a result the piston 288 is urged upwardly in the cylinder 284 causing the leading end of a ready web supply roll supported on a lower nip roll 358, as seen in FIG. l, to be adhered to web unwinding from the upper web supply station. lf,

on the other hand, the switch 356 is shifted so that the solenoid 292 is energized, the spool 290 is shifted upwardly, connecting the lower chamber of the cylinder 282 to the regulator 278 and the upper chamber to atmosphere. As a result the piston 286 is urged downwardly causing the leading end of a ready web from the upper unwind station, supported on an upper nip `roll 360, FIG. 1, to be adhered to a running web from the lower unwind station.

The closing of the contacts TD1-B also causes the energization of a second time delay relay TD2I which has a single pair of normally `closed contacts TD2-A as already indicated. The relay TD2 is adjusted so that after a brief interval of one to two seconds the relay contacts TD2-A are opened. When the relay contacts TD2-A open, the relay coil 1CR is de-energized, causing the relay contacts 1CR-A and 1CR-B to open. T-he opening of the contacts 1CRA causes the stoppage of the vacuum pump motor 344 .and the opening of the contacts 1CR-B causes the secondary line 342 to be deenergized. When the line 342 is yde-energized the ow of current to the relay coils 2CR and TD1 is cut off so that the contacts 2CR-A return to their normally open position and the contacts TD1-A and TD1-B return to their normally closed and normally open positions respectively.

The solenoid 302 has already been de-energized and the effect of this has been to return control of the air pressure supplied to the brake pa-ds Eby the cam controlled pressure regulator 144, which may be adjusted .and/or have its cam 140 so formed as to supply no braking pressure to the brake pads while the storage festoon 30 is largely depleted of web, for example, While the dancer assembly 80 is in the lower half or two thirds of its travel. This control condition by the regulator 144 continues throughout normal unwinding of the web with the `addition of pulses of compressed air at a higher pressure Ifrom the regulator 312 being fed to the brakes through the shuttle valve 304.

Electrical circuit elements related to the valve 312 and the switch 160 for providing pulses of air under a high pressure to the brake pads 230 and 236 are also shown in FIG. 12 and include a time delay relay TD3 in series across the line with the switch 160. The relay TD3 may be adjusted to provide a predetermined pulse width typically on the order of one-quarter second during which the solenoid 318 of FIG. 1l is energizedto Iprovide air to the shuttle valve 304 from the regulator 312. This is accomplished by the single set of normally closed contacts TD3-A operated by the relay coil TD3. At the end of the typical `quarter second time interval, the contacts TD3-A open to terminate the energization of solenoid 318. The circuitry for energizing the solenoid 318 includes the switch 150 which is cam controlled to render the damping circuit effective only approximately during the lower two-thirds of the travel of the dancer assembly 80. In parallel with the switch 150 and the solenoid 318 is a relay coil 3CR having a single pair of normally open contacts SCR-A which are in parallel with the switch 160 and accordingly serve as latching contacts to keep the relay coil TD3 and the solenoid 318 energized until the contacts TD3-A open. Therefore, the time that the solenoid 318 is energized and permits the passage of compressed air from the regulator 312 to the shuttle valve 304 is independent of the period during which the switch 160 is closed by the teeth of the pinion 166.

It will be appreciated from the foregoing description of the damping circuit that a predetermined pulse Width of air to the shuttle valve 304 is obtained by the setting of the relay including the coil TD3; that the pressure supplied during the pulse is adjustable by the setting of the regulator 312; that the portion of dancer assembly rise which is subjected to the pulses is controlled by the form of the cam 146 seen in FIG. 3 and that the repetition rate at which the switch 160 closes to initiate pulses is controlled by the ratio of the number of teeth Vof the pinion 164 and the gear 166 which may be considered as change gears for this purpose. Thus, great flexibility is provided for controlling Webs of widely divergent physical properties being fed to web consuming machines having very highly varied demand speeds so that the web supply rolls under control may be regulated in their acceleration Without encountering rapid motion and corresponding momentum of the dancer assembly 80.

The path of the web :as well as the advantageous manner in which it is threaded through the apparatus will now be -described with reference to FIGS. 7 and 8 relating to a double dancer roll conguration. In FIG. 7, web is shown unwinding from the roll 32 at the upper unwind station and in doing so it passes over a guide roll 366 and then through the web splicing device which includes lower and upper nip rolls 3-58 and 360. While unwinding from the roll 32, the web contacts only the upper nip roll 360, since the nip rolls are maintained in spaced relationship during nor-mal unwinding. From the web splicing device 36, the web passes successively to guide rolls 368, 370, and 372 :and then enters the festoon 30 passing successively over the rolls 44, 68, 42, 66, 40, 64, 38 and 62 to guide a roll 376 and then doubling back upon itself toward the front of the apparatus. From the guide roll 376 the web then passes successively over the rolls 54, 46, 56, 48, 58, 50, and 60 fand the g-uide roll 52 and out to the web consuming machine. When web is unwinding from the roll 34 at the lower unwind station the path is essentially the same except that before reaching the guide roll 368, the web passes over a guide roll 374 and the lower nip roll 358 out of contact with the upper nip roll 360. It is thus seen that the double roll configuration which has now been described makes possible the fitting of bights closely one within the other so as approximately to double the storage capacity available with the apparatus of the above identiied application. Thus the bight extending between the outboard dancer roll 54 and over the idler roll 46 to the outboard `dancer roll 56 is disposed substantially within the bight extending between the inboard dancer roll 62 over the outboard idler roll 38 and to the inboard dancer roll 64.

It will be seen in FIG. 8 that 'by cutting the supply of compressed air to the dancer assembly cylinders 128 and 130, the dancer assembly is lowered to a position in which the outboard dancer rolls 54, 56, 58 and 60 are below the inboard idler rolls 46, 48, 50 and 52. Under these conditions the web from the roll 32 may conveniently be threaded through the lapparatus by drawing a length of web over the guide roll 366, the upper nip roll 360, the guide rolls 368, 370 and 372 and looping the web back and forth as shown in FIG. 8. The loading path of the web going rearwardly is above the inboard dancers 68, `66, 64, 62 and below the outboard idlers 44, 42, 40, 38 and the guide roll 376. The web is then brought forward from the guide roll 376 above the outboard dancer -rolls 54, 56, 58 and 60 and below the inboard idler rolls 46, 48, 50 and 52. The length of web drawn from the roll 32 should be sufiicient to permit that part of the web extending to the right of the idler roll 52 in FIG. 8, to be started in and securely gripped by the web consuming machine. The valve 258 is then opened to provide air under pressure to the cylinders 128 and 130 and a tension is thereby applied to the web which starts the roll 32 to turn in an unwinding direction as the web consuming machine is started slowly and then lgradually :accelerated to its normal operating speed.

There is shown in FIG. 9, apparatus of essentially the same design as that depicted in FIG. 7 with the exception that a triple roll configuration is employed in order to increase further the capacity of its web storage festoon. The apparatus of FIG. 9 is shown having mounted in it an upper web supply roll 3180 and a lower web supply roll 382. This apparatus comprisesfour sets of three vertically aligned dancer rolls cooperating with four sets of vertically aligned idler rolls. As in the case of the double roll configuration the largest roll in each set is mounted outboard and the smallest roll is mounted inboard but a roll of intermediate diameter is mounted between the largest and smallest rolls. The dancer assembly comprises outboard dancer rolls 384, 386, 388 and 390 arranged in sets respectively with intermediate dancer rolls 392, 394, 396 and 398 and further coupled in sets respectively with inboard dancer rolls 400, 402, 404 and 406. The sets of idler rolls comprise the outboard idler rolls 408, 410, 412 and 414 coupled in sets respectively with intermediate idler rolls 416, l418, 420 and 422 and with inboard idler rolls 424, 426, 428 and 430. In addition to the idler and dancer rolls, the apparatus of FIG. 9 also comprises upper and lower nip rolls 434 and 436 and guide rolls 438, 440, 442 and 444. The whole dancer assembly is guided in its verticalrmovement toward and away from the idler rolls on a pair of rails, one of which is indicated by the reference numeral 446 as shown in FIGS. 9 and 10.

While web is unwinding from the roll 380 at the upper unwind station, it passes successively over the guide roll 438, the upper nip roll 434 and the guide roll 440 into the festoon in which it alternates between idler rolls and dancer rolls from back to front, left to right in FIG. 9, then front to back and then again from back to front. Thus the path of the web from the guide roll 440 is successively over the rolls 424, 384, 426, 386, 428, 388, 430 and 390 to the `guide roll 442 at the front of the apparatus. From the guide roll 442, the web is guided toward the rear of the apparatus passing successively over the rolls 398, 422, 396, 420, 394, 418, 392 and 4l6. From the idler roll 416, the web passes over the idler roll 408 and then returns toward the front of the apparatus passing successively over the rolls 400, 410, 402, 412, 404, 414- and 406 to the output guide roll 444 and from this roll to the web consuming machine. Web unwinding from the roll 382 follows essentially the same path except that it passes from the web supply roll over a guide roll 448, the lower nip roll 436, the guide roll 440 and from there into the storage festoon.

It is seen from the foregoing that apparatus having a triple roll configuration is adapted to the storage of approximately 50% more web than the double roll configuration in the parameters of equal floor space and height of the apparatus. The storage density of the apparatus may be appreciated from the fact that the web is disposed in three sets of bights lying essentially one within the other. Thus, for example, the bight from the dancer roll 400, over the idler roll 410, to the dancer roll 402 has disposed largely within it a second bight extending from the intermediate dancer roll 392, over the idler roll 418, to the dancer roll 394 and a third bight extending from the outboard dancer roll 384, over the inboard idler roll 426, to the outboard dancer roll 386.

As in the case of the apparatus having the double roll configuration provision is made in the apparatus of FIGS. 9 and l() for ease of threading of the web for initial startup as seen in FIG. 9. After the dancer assembly has been depressed to the position of FIG. l0, a length of web is drawn from the upper web supply roll 380 over the guide roll 438, the upper nip roll 434 and the guide roll 440 and then forward through the apparatus, that is from left to right as seen in FIG. l at a level below the inboard idler rolls 424, 426, 428 and 430 and above the outboard dancer rolls 384, 386, 388 and 390. The web is then passed around the guide roll 442 at the front of the apparatus and returned rearwardly at a level below the intermediate idler rolls 422, 420, 418 and 416 and over the intermediate dancer rolls 398, 396, 394, and 392 to the outboard idler roll 408. From the outboard idler roll 408 the web is again brought forward at a level below the outboard idler rolls 410, 412, and 414 and above the inboard dancer rolls 400, 402, 404 and 406 into engagement with the guide roll 444 and to the web consuming machine. The lweb is drawn slowly while the dancer rolls are in the position shown in FIG. l0 and a length of the web is engaged by and firmly gripped in the web consuming machine. Thereafter the dancer rolls are urged upwardly in a manner similar to that described with reference to the apparatus of FIGS. 7 and 8 in which the double roll configuration is employed.

The combination of one of the festoons already described whether of double or triple roll configuration with the control devices also included in the present apparatus yields a highly accurate regulation and conditioning of web passing from a supply roll to a consuming machine at an elevated speed of throughput. However, substantial advantages accrue from the use of parts of the present disclosure independently of the others or in different contexts. It is accordingly not our intention that the illustrative embodiments of the foregoing specification be taken by way of limitation but that the scope of the invention be interpreted in terms of the accompanying claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for controlling the unwinding of web from a supply roll to a web consuming machine comprising at least two sets of idler rolls and two sets of dancer rolls, each set including at least two spaced apart rolls aligned in the direction of web movement for defining a web path in which a bight of web turning near its midpoint about a single roll is disposed essentially within another -bight of web also turning near its midpoint about a single roll and in 'which each `bight extends between dancer and idler rolls.

2. Apparatus according to claim 1 further characteriaed in that the rolls in each set are of different diameters and that the larger roll in each set is positioned outboard.

3. Apparatus according to claim 1 further comprising means for urging the dancer rolls in a web storing direction.

4. Apparatus according to claim 1 further comprising means for urging the dancer rolls in a direction to apply tension to the web for accelerating the lweb supply roll from a stationary condition to the demand speed of the web consuming machine, and means for supplying intermittent pulses of braking force to the web supply roll in response to its speed exceeding the demand speed of the web consuming machine.

5. Apparatus according to claim 4 further characterized in that the means for supplying pulses includes means for initiating the pulses at a rate proportional to the excess of supply roll speed over demand speed.

6. Apparatus for controlling the unwinding of web from a supply roll to a web consuming machine, comprising a dancer assembly including at least one idler roll rotatable about a stationary axis and at least one dancer roll having a path of travel toward and away from the idler roll, means for urging the dancer roll along its path from an empty condition nearest the idler roll to a filled condition most remote from the idler roll, a fluid operated brake coupled to the web supply roll and means for supplying discrete fiuid pressure pulses to the brake in response to and at a rate proportional to the speed of motion of the dancer roll away from the idler roll during a part of its travel.

7. Apparatus according to claim 6 further comprising means for rendering the pulse supplying means inoperative during a part of the travel of the dancer roll.

8. Apparatus according to claim 7 further comprising means for supplying a continuous fluid pressure to the brake as the dancer roll approaches a filled condition after the pulse supplying means has been rendered inoperative.

9. Apparatus according to claim 8 further comprising means for increasing the uid pressure as the dancer roll approaches the filled condition.

10. Apparatus according to claim 6 further comprising means for varying the duration of each puise.

11. Apparatus according to claim 6 further comprising means for varying the number of Huid pressure pulses for 13 a given length of travel of the dancer roll away from the idler roll.

12. Apparatus according to claim 6 further comprising a yoke upon which the dancer roll is supporte-d for movement toward and away from the idler roll and uid actuated `means for -urging the yoke away from the idler roll.

13. Web storage apparatus comprising a frame, a plurality of sets of idler rolls rotatable about stationary axes on the frame, a plurality of sets of dancer rolls, each set of rolls comprising at least t-wo rolls generally aligned in a web storage direction and dening between idler and dancer rolls a web path for a plurality of bights each formed over a single roll and nested one within the other, means urging the dancer rolls away from the idler rolls and means translating the changeable relative positions of dancer and idler rolls into a variable output signal.

14. Web storage apparatus according to claim 13 in which each set of idler and dancer rolls consists of rolls of different diameters and in which the larger roll in each set is positioned outboard.

15. Web storage apparatus comprising a frame, a plurality of sets of aligned idler rolls rotatable about stationary axes on the frame, a plurality of sets of dancer rolls, each set of rolls comprising at least two rolls generally aligned in a web storage direction, the sets of dancer rolls being offset in a direction normal to the web storage direction from the sets of idler rolls and defining between idler and dancer rolls a web path for a plurality of bights each formed over a single roll and nested one within the other, means urging the dancer rolls away from the idler rolls, and means for temporarily disabling the urging means for the dancer rolls whereby the sets of dancer rolls are located in a web loading position, interposed between sets o;f idler rolls.

References Cited UNITED STATES PATENTS LEONARD D. CHRISTIAN, Prmrzry Examiner. 

1. APPARATUS FOR CONTROLLING THE UNWINDING OF WEB FROM A SUPPLY ROLL TO A WEB CONSUMING MACHINE COMPRISING AT LEAST TWO SEATS OF IDLER ROLLS AND TWO SETS OF DANCER ROLLS, EACH SET INCLUDING AT LEAST TWO SPACED APART ROLLS ALIGNED IN THE DIRECTION OF WEB MOVEMENT FOR DEFINING A WEB PATH IN WHICH A BIGHT OF WEB TURNING NEAR ITS MIDPOINT ABOUT A SINGLE ROLL IS DISPOSED ESSENTIALLY WITHIN ANOTHER BIGHT OF WEB ALSO TURNING NEAR ITS MIDPOINT ABOUT A SINGLE ROLL AND IN WHICH EACH BIGHT EXTENDS BETWEEN DANCER AND IDLER ROLLS. 